NVA amps

mosfet said:
What's high resistance? I've measured the loop DCR of DNM Reson loudspeaker cable and found this to be around 0.15 ohms per meter. Sufficient to cause audible level losses into 4 ohm loads (loudspeaker minima impedance) for 3 meters of cable.

High resistance loudspeaker cables are plain daft. But then again, so are a lot of other things. Subjectivism rules? Maybe. I quite liked the DNM cable.
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I've noticed the same thing with the DNM cable and you can replicate the same effect with thin bell wire - light bass.
I notice the same effect with LS1 on wide bandwidth speaker systems and this also has higher than average resistance - average being the standard issue stranded stuff from Linn/Naim/Rega/QED etc.

Tests have shown that the high inductance of DNM can cause HF roll-off of around 1db up at 18-20khz. This gives the DNM its hallmark mid forward 'clean' sound with good vocal projection, but lacking a little bottom end weight and top end air.
 
I've noticed the same thing with the DNM cable and you can replicate the same effect with thin bell wire - light bass.
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If you have a look at the linear resistance for 1/0.6mm single core equipment wire Rob, you'll see it's around 0.064 ohms per meter. Thus the loop resistance for a loudspeaker cable based on a similar (the same?) dimension of wire will be double this per meter. For a one meter length about 0.13 ohms - or as I measured the DNM loudspeaker cable about 0.15 ohms.

A three meter length having loop resistance of about 0.45ohms equates to around 1dB level loss into a 4 ohm load. A nominally rated 8 ohm loudspeaker will typically dip to around 4 ohms thru the midbass. So it's not difficult to see how loudspeaker cable having relatively high resistance can cause audible frequency-specific level losses.

Not necessarily a bad thing since it's all subjective, but neither neutral in the sense of the loudspeaker cable having no effect on the frequency response of a hi-fi system.

By keeping the loop resistance of a loudspeaker cable to no more than 5% of the minimum loudspeaker impedance - for any given length of cable - is a good rule of thumb.
 
mosfet said:
If you have a look at the linear resistance for 1/0.6mm single core equipment wire Rob, you'll see it's around 0.064 ohms per meter. Thus the loop resistance for a loudspeaker cable based on a similar (the same?) dimension of wire will be double this per meter. For a one meter length about 0.13 ohms - or as I measured the DNM loudspeaker cable about 0.15 ohms.

A three meter length having loop resistance of about 0.45ohms equates to around 1dB level loss into a 4 ohm load. A nominally rated 8 ohm loudspeaker will typically dip to around 4 ohms thru the midbass. So it's not difficult to see how loudspeaker cable having relatively high resistance can cause audible frequency-specific level losses.

Not necessarily a bad thing since it's all subjective, but neither neutral in the sense of the loudspeaker cable having no effect on the frequency response of a hi-fi system.

By keeping the loop resistance of a loudspeaker cable to no more than 5% of the minimum loudspeaker impedance - for any given length of cable - is a good rule of thumb.
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So are you saying that the output impedance / damping factor of the amplifier used has no part in this?
 
The output impedance of the amplifier should of course be considered Richard - as you said earlier. However even if amplifier output impedance is very low this will not negate level losses attributable to (relatively high) cable resistance. Such as the example given above.

Indeed using high resistance loudspeaker cable with an amplifier with admirably low output impedance is rather counter productive. The advantages of high damping factor are lost or reduced.
 
JonR said:
Hi Richard,

A quick question then, if I may, and apologies in advance if it seems like a silly one!

Could your P50 passive preamp work in conjunction with a Naim NAP200 power amp, such as I use in my system. The speakers I use are Neat Motive 2s by the way.

Many thanks in advance for any reply.

Regards,

Jon
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Hi John

As I replied before to you I have no experience of this combo, but I have just recieved an email from someone who has tried it with NAP160 and Neat Petites so the results should be valid to you. His post below.

Hello Richard,

I've been extremely impressed by the NVA products I've
bought from you to date. In fact your passive pre has replaced my Audionote M2 in my main system with great results.

In the future I intend to add a pair of mono blocks to my modded
NAP160 and bi-amp my Neats but not until funds allow
unfortunately.

At the moment I'm interested in a good quality headphone amp to use my Sennheiser 650s with, I read about the AP10H and wonder if it might fit the bill? Are you currently selling these?
Is it possible to incorporate into a system such as mine (NVA P50/NAP160) or is it designed purely as a stand alone amp?

Thanks,
Paul Neeve

Now one swallow doesn't make a summer, but it looks as though there could be potential!

Richard
 
There is one thing and one thing only that puts me off buying these amps, and that is a lack of remote volume control. Now, I fully understand the reasoning behind not having one, but for me at least with most of my listening done in the evening, the ability to lower the volume if a particularly loud track comes on is indespensible. I hope in the future that NVA find a way around this, for if they do they will be able to count me among their customers.
 
aquapiranha said:
There is one thing and one thing only that puts me off buying these amps, and that is a lack of remote volume control. Now, I fully understand the reasoning behind not having one, but for me at least with most of my listening done in the evening, the ability to lower the volume if a particularly loud track comes on is indespensible. I hope in the future that NVA find a way around this, for if they do they will be able to count me among their customers.
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I really don't understand this. If you are disabled it's fair enough, otherwise why is it such an effort to walk a few metres to change the volume?
 
aquapiranha said:
There is one thing and one thing only that puts me off buying these amps, and that is a lack of remote volume control. Now, I fully understand the reasoning behind not having one, but for me at least with most of my listening done in the evening, the ability to lower the volume if a particularly loud track comes on is indespensible. I hope in the future that NVA find a way around this, for if they do they will be able to count me among their customers.
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I have investigated this problem and have designed control extension manipulators. Being very long tubes (like speaker cable you order by length) there are disadvantages over remote controls as you have to angle the units so that the tubes reach your listening seat. There is also the problem of having to step over them as you go around the room. The prototypes are cardboard but we are looking into flexible tubing (hose) so it can go around furniture or under the carpet. Sounds so much better than an electronic remote it is frightening and it doesn't need batteries either.

(Imagining the the background music to looney toons [oh don't you miss 'em!!!]) "erh - thats all folks"

Richard
 
Richard Dunn said:
I have investigated this problem and have designed control extension manipulators. Being very long tubes (like speaker cable you order by length) there are disadvantages over remote controls as you have to angle the units so that the tubes reach your listening seat. There is also the problem of having to step over them as you go around the room. The prototypes are cardboard but we are looking into flexible tubing (hose) so it can go around furniture or under the carpet. Sounds so much better than an electronic remote it is frightening and it doesn't need batteries either.

(Imagining the the background music to looney toons [oh don't you miss 'em!!!]) "erh - thats all folks"

Richard
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Lol, I figured you would say something along those lines! c'est la vie!
 
Hi Richard,

Thanks for that, though if you have seen some messages I have sent you via 'another medium' you may find it's all pretty moot now :)

Cheers,

Jon
 
JonR said:
Hi Richard,

Thanks for that, though if you have seen some messages I have sent you via 'another medium' you may find it's all pretty moot now :)

Cheers,

Jon
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Sorry Jon you have completely lost me :confused:

Direct me to this other medium if you would. Another forum?? I only know this one.

Richard
 
Hi Richard,

Glad to see your products and ideas are available for people to buy. I very much like the ideas behind the products and the simplicity of approach - something that in this day and age is rare.

Without going into subjective detail (yes or no will do), with high efficiency loudspeakers would a lower powered NVA amp be better than a higher powered NVA amp?

Also would it be worth trying in a Linn system with Kolektor/LK140?

Andrew
 
Richard Dunn said:
Sorry Jon you have completely lost me :confused:

Direct me to this other medium if you would. Another forum?? I only know this one.
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Richard,

I have sent you a private message.

Regards,

Jon
 
AndrewR said:
Hi Richard,

Glad to see your products and ideas are available for people to buy. I very much like the ideas behind the products and the simplicity of approach - something that in this day and age is rare.

Without going into subjective detail (yes or no will do), with high efficiency loudspeakers would a lower powered NVA amp be better than a higher powered NVA amp?

Also would it be worth trying in a Linn system with Kolektor/LK140?

Andrew
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Oh dear - I hate these questions - it is so arogant to pronounce *my opinion* as though it is of any more importance than anyone else. It is *all* subjective - it is all about energy (in this form music) and how that moves through your mind and body (and binds with your spirit).

How about I just say I haven't got a bloody clue, but I would welcome you trying and seeing, and if you don't like then send it back.

The only obvious thing is that lower power will only drive higher efficiency, where as visa(ing) the versa wont. But power is pretty meaningless. The only answer is systems, which includes you(r) peculiarities, your listening room peculiarities, your musical peculiarities etc. In NVA's case lower power just means it costs less. In order to cost less it uses smaller case, smaller transformer, smaller capacitors, less voltage rail as the smaller case will not cope thermally beyond a certain point etc etc. The bigger amps basically give you more (quantity and quality) of the same music.

Also I am getting worried that this is starting to look like I am spamming the forum. I don't want to use this forum as a selling medium. BUT is so difficult to be a designer (what ever that is!), and also just try to be a mate (friend) and a normal list contributor. I genuinly like the way my designs reproduce music, that is my aim. I do not design for commercial reason. That means I only satisfy people who agree or are sympathetic to *my* peculiarities. I will always respect someone who disagrees. I just wish someone would come on the forum and say "I tried NVA and I didn't like it" then we would get some balance. I always get embarrassed by praise.

Richard
 
Richard Dunn said:
Oh dear - I hate these questions - it is so arogant to pronounce *my opinion* as though it is of any more importance than anyone else. It is *all* subjective - it is all about energy (in this form music) and how that moves through your mind and body (and binds with your spirit).

How about I just say I haven't got a bloody clue, but I would welcome you trying and seeing, and if you don't like then send it back.

The only obvious thing is that lower power will only drive higher efficiency, where as visa(ing) the versa wont. But power is pretty meaningless. The only answer is systems, which includes you(r) peculiarities, your listening room peculiarities, your musical peculiarities etc. In NVA's case lower power just means it costs less. In order to cost less it uses smaller case, smaller transformer, smaller capacitors, less voltage rail as the smaller case will not cope thermally beyond a certain point etc etc. The bigger amps basically give you more (quantity and quality) of the same music.

Also I am getting worried that this is starting to look like I am spamming the forum. I don't want to use this forum as a selling medium. BUT is so difficult to be a designer (what ever that is!), and also just try to be a mate (friend) and a normal list contributor. I genuinly like the way my designs reproduce music, that is my aim. I do not design for commercial reason. That means I only satisfy people who agree or are sympathetic to *my* peculiarities. I will always respect someone who disagrees. I just wish someone would come on the forum and say "I tried NVA and I didn't like it" then we would get some balance. I always get embarrassed by praise.

Richard
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Very well said ......Mostly you need to listen and see if the sound moves you. I've always liked NVA but have never been in a position to buy....At the time [mid 80's] they were beyond my pocket, and now I've gone a different route ! but its good to have a chance to chat to the builders rather than just the users and sellers !
 
zanash said:
Very well said ......Mostly you need to listen and see if the sound moves you.
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Have you ever tried to work with what it is that is moving, and why it is doing it. Energetic stimulation is a fascinating process.

Your body is moved by rhythm and beat. This is a quantitative experience. I take you back to the first West Indian disco type work in the UK in the late 60's early 70's. During the 3 day week I was managing the GW Smith and Co (radio) ltd Edgware Road shop in London, and I heard some pretty amazing beat and rhythm from 18inch Goodmans paper coned drivers mounted on marine ply baffle plates (no case), Linear Conchord valve amp, Garrard SP25 with Goldring or Shure. You moved! It became a shop joke "hey man - any 18inch Goodmans" we were regularly out of stock, 15inch wouldn't do (L0L). Great people though,full of *life*. Different now, sadly.

Your mind is moved by clarity and definition. Very much the prerogative of the objectivist. The body system mentioned above had none of that, it was mush! but it was music!

Your spirit is moved by the emotional content of the music and its reproduction. Manifested by Qi flow through the body, skin sensation, little hairs rising on the back of the neck. The centring of your emotional state (relaxation). Very much the realm of subjective appreciation.

Different people *get off* on these aspects in differing quantity and balance, but all have to be there IMO to get the full *hit*. And that is the point, you are drug addicts!!! playing with internally stimulation to produce the natural pleasure drugs produced by the human body and mind.

Some odd variations have grown up though (here I start to be a little controversial). The Linn music method of assessment seems to me to be an objectivist outline of a subjective imperitive. Mildly peculiar as it roots all of these stimulations through the frontal lobe. Self defeating IMO.

You will find it is interesting to explore the results of the stimulation as well as just the source. Music listening is a form of meditation. The frontal lobe is the killer to all meditative techniques and states. Switch off the mind, don't intellectualise the experience, just *feel it* and live it.

If you ever can't get into your music, as the stress related reactions from your life are too strong, just turn down the lights take away all visual and audible stimulation. Focus your mind on the sound and the feel of your breathing and breath with your stomach or lower abdomen. Slow your breathing down to half the normal rate and feel your stomach rise and fall with the beat of the breath. Still your mind, don't allow extrenuous thought. Feel the rising energy that is creating the stress and take it with your mind back to your centre (centre of gravity) where you are breathing from. 10 minutes of that equates to an extra £5000 on your hi-fi :D :) :SLEEP: Next day seems so much clearer!

Richard
 
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Yes ..... though It was more in the way of assessing new or different kit....

but I do agree ......"there's more in heaven and earth" etc, than just science and specifications. i also rather like this quote

"Round about the accredited and orderly facts of every science there ever floats a sort of dust-cloud of exceptional observations, of occurrences minute and irregular and seldom met with, which it always proves more easy to ignore than to attend to... Anyone will renovate his science who will steadily look after the irregular phenomena, and when science is renewed, its new formulas often have more of the voice of the exceptions in them than of what were supposed to be the rules."
- William James

I'm a big believer in some of the more alternative "energies" even though I have been involved with conventional science wisdom for my whole life. I have manipulated the "beach ball" in Tai chi, I also dowse, both of which need breathing control and a centering [grounding] of the self to be effective. Though I think some of this may be too much for the more vociferous naysayers that inhabit the darker areas of this forum!
 
zanash said:
Yes ..... though It was more in the way of assessing new or different kit....

but I do agree ......"there's more in heaven and earth" etc, than just science and specifications. i also rather like this quote

"Round about the accredited and orderly facts of every science there ever floats a sort of dust-cloud of exceptional observations, of occurrences minute and irregular and seldom met with, which it always proves more easy to ignore than to attend to... Anyone will renovate his science who will steadily look after the irregular phenomena, and when science is renewed, its new formulas often have more of the voice of the exceptions in them than of what were supposed to be the rules."
- William James

I'm a big believer in some of the more alternative "energies" even though I have been involved with conventional science wisdom for my whole life. I have manipulated the "beach ball" in Tai chi, I also dowse, both of which need breathing control and a centering [grounding] of the self to be effective. Though I think some of this may be too much for the more vociferous naysayers that inhabit the darker areas of this forum!
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We largely bounce around under the control of our desire.
Three ages of man
Youth = body - disco - dance - LOUD! always looking for *more* = better fun.
Grown-up = intellect - the hi-fi people :) superiority! always looking for *more* = better satisfying the ego.
Growing-down = spirit - the music people :rolleyes: seniority! always looking for *more* = better justifying self.

Answer - don't let it control you - you control it. Take your own life where you want it, don't let it take you. Sensitivity.

There you go - you see really I am just a pretentious **** :D

Richard
 

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